6-48 & 8-40 Combo Optics Mount Screw Kit – 48 Piece Assortment Keep the right mounting screws on hand for firearm optic installations and repairs. This dual-thread screw assortment includes 6-48 and 8-40 thread sizes with multiple lengths and head styles to help match different bases, rails, and mounts. Built from Class 12.9 high-strength alloy steel for demanding mounting applications. Note: Firearm mounting patterns vary by brand/model. Verify thread size (6-48 or 8-40) and required screw length before installation. If you're unsure, compare to your original screws or confirm with the mount/base manufacturer. Use proper torque and threadlocker per manufacturer recommendations.